Detergent composition



Patented June 30, 1931 UNITED STATES PATENT OFFICE WILLIAM J. ZICK, OF HEATHGBOFT, LONDON, ENGLAND, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY DETERGENT controsrrrorr No Drawing.

The present invention relates to detergents and more specifically comprises an improved naphtha soap. The composition of my improved detergent and the method of its manufacture will be fully understood from the following description.

It is well known that various ingredients have been added to an ordinary soap commonly produced by the saponification of an animal fat or a vegetable oil, or mixture of like fatty substances in themanufacture of soaps intended for certain particular and frequently limited uses. I have now found that particularly desirable properties are imparted to an ordinary soap by the addition thereto of a small proportion of a naphthenic acid or mixtures thereof.

N aphthenic hydrocarbons, as is well known, are naturally occurring substances present in comparatively small quantities in petroleum oil, particularly in Russian and Galician mineral oil, but are also found in some oils produced'in' this country; for example in oils from some districts in the Texas and Mid-continent fields. When such oils are distilled and thevarious fractions are treated in the usual manner with suitable purifying agents, the naphthenic acids are found present in the separated sludges. When the acids are present in the sludges resulting from the treatment of an oil containing naphthenic hydrocarbons with an aqueous solution of caustic soda, the acids are of course found in the form of their sodium salts. The acids may be readily obtained from their salts by adding the necessary quantity of sulfuric acid and distilling the separated naphthenic acids. The recovered acids so obtained are pale yellow, oily-like liquids of relatively low viscosity. The acids may be furtherpurified, if desired, by subjecting them to a second distillation step fol lowed by filtration through a medium, such as fullers earth, charcoal, silica gel and the like. Naphthenic acid is also found as a natural constituent of certain mineral oils and may be obtained therefrom by distilling the oil over 'a caustic solution, and treating the residual sludge from the distillation process with a mineral acid. The separated naph- Application filed November 1, 1926. Serial No. 145,716.

thenic acid is then purified by distillation and filtration, if desired.

The naphthenic acids so obtained may be incorporated into a soap preferably in proportions up to 4 to 5% by weight of the soap, and desirably, with-the addition of small proportions, for example not more than 0.5% by weight (preferably about 0.25%) of a mineral oil fraction such as kerosene, aheavy kerosene, or a relatively light white 011 the specific gravity of which does not exceed 0.87. The naphthenic acid and the kerosene may be added to the soap at any desirable stage during its manufacture after the removal of excess caustic soda from the soap, as it is an object of this invention to manufacture a soap containing free naphthenic acid and not substantial quantities of salts thereof incorporated in the soap. It is, of course, possible, especially in the case of some of the cheaper grades of laundry soap wherein the excess of caustic alkali is not carefully and completel removed from the soap, that a portion of t e-naphthenic acid added may be neutralized by the residual caustic, but in such cases it is my object to add a sufficient quantity of the naphthenic acid that the resulting soap shall contain not more than approximately 4 to 5% by Weight of the unneutralized naphthenic acids.

Although I have described my invention with reference to certain specific details, it will be understood that this is for the purpose of illustration to make my invention clearly understood and is not limitative, and that changes may be made in the proportions of the various ingredients employed which come within the spirit and scope of the claims appended hereto, in which I intend to claim all novelty inherent in my invention as permissible in view of the prior art.

lVhat I claim is:

1. A detergent composition comprising a soap, substantially free from alkali, containing not more than 5% by weight of an uncombined naphthenic acid and less than 0.5% of mineral oil of the type of kerosene and light white oil the specific gravity of which does not exceed 0.87.

2. A detergent composition comprising a soap, substantially free from alkali, containing substantially 4% by weight of a free naphthenic acid and substantially 025% by welght of mineral oil of the ty e of kerosene and light white oil the specific gravity of which does not exceed 0.87.

3. A detergent composition comprising a soap, substantially free from alkali, containing substantially 4% by weight of a free naphthenic acid and substantially 0.25% by. weight of kerosene.

' w. J. ZICK. 

